{"type": "FeatureCollection", "features": [{"id": "10.1007/s11104-008-9614-4", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-20T16:14:41Z", "type": "Journal Article", "created": "2008-04-29", "title": "Assessment Of Soil Nitrogen And Phosphorous Availability Under Elevated Co2 And N-Fertilization In A Short Rotation Poplar Plantation", "description": "Photosynthetic stimulation by elevated [CO2] is largely regulated by nitrogen and phosphorus availability in the soil. During a 6 year Free Air CO2 Enrichment (FACE) experiment with poplar trees in two short rotations, inorganic forms of soil nitrogen, extractable phosphorus, microbial and total nitrogen were assessed. Moreover, in situ and potential nitrogen mineralization, as well as enzymatic activities, were determined as measures of nutrient cycling. The aim of this study was to evaluate the effects of elevated [CO2] and fertilization on: (1) N mineralization and immobilization processes; (2) soil nutrient availability; and (3) soil enzyme activity, as an indication of microbial and plant nutrient acquisition activity. Independent of any treatment, total soil N increased by 23% in the plantation after 6 years due to afforestation. Nitrification was the main process influencing inorganic N availability in soil, while ammonification being null or even negative. Ammonium was mostly affected by microbial immobilization and positively related to total N and microbial biomass N. Elevated [CO2] negatively influenced nitrification under unfertilised treatment by 44% and consequently nitrate availability by 30% on average. Microbial N immobilization was stimulated by [CO2] enrichment and probably enhanced the transformation of large amounts of N into organic forms less accessible to plants. The significant enhancement of enzyme activities under elevated [CO2] reflected an increase in nutrient acquisition activity in the soil, as well as an increase of fungal population. Nitrogen fertilization did not influence N availability and cycling, but acted as a negative feed-back on phosphorus availability under elevated CO2.", "keywords": ["2. Zero hunger", "atmospheric co2", "enrichment face", "microbial biomass-c", "use efficiency", "ponderosa pine", "04 agricultural and veterinary sciences", "15. Life on land", "carbon-dioxide", "01 natural sciences", "forest", "0401 agriculture", " forestry", " and fisheries", "increases", "organic-matter", "arylsulfatase activity", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.1007/s11104-008-9614-4"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%20and%20Soil", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s11104-008-9614-4", "name": "item", "description": "10.1007/s11104-008-9614-4", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s11104-008-9614-4"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2008-04-30T00:00:00Z"}}, {"id": "10.1111/j.1365-2486.2004.00862.x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-20T16:17:34Z", "type": "Journal Article", "created": "2004-11-16", "title": "Decomposition Of Soil And Plant Carbon From Pasture Systems After 9 Years Of Exposure To Elevated Co2: Impact On C Cycling And Modeling", "description": "Abstract<p>Elevated atmospheric CO2 may alter decomposition rates through changes in plant material quality and through its impact on soil microbial activity. This study examines whether plant material produced under elevated CO2 decomposes differently from plant material produced under ambient CO2. Moreover, a long\uffe2\uff80\uff90term experiment offered a unique opportunity to evaluate assumptions about C cycling under elevated CO2 made in coupled climate\uffe2\uff80\uff93soil organic matter (SOM) models. Trifolium repens and Lolium perenne plant materials, produced under elevated (60\uffe2\uff80\uff83Pa) and ambient CO2 at two levels of N fertilizer (140 vs. 560\uffe2\uff80\uff83kg\uffe2\uff80\uff83ha\uffe2\uff88\uff921\uffe2\uff80\uff83yr\uffe2\uff88\uff921), were incubated in soil for 90 days. Soils and plant materials used for the incubation had been exposed to ambient and elevated CO2 under free air carbon dioxide enrichment conditions and had received the N fertilizer for 9 years. The rate of decomposition of L. perenne and T. repens plant materials was unaffected by elevated atmospheric CO2 and rate of N fertilization. Increases in L. perenne plant material C\uffe2\uff80\uff83:\uffe2\uff80\uff83N ratio under elevated CO2 did not affect decomposition rates of the plant material. If under prolonged elevated CO2 changes in soil microbial dynamics had occurred, they were not reflected in the rate of decomposition of the plant material. Only soil respiration under L. perenne, with or without incorporation of plant material, from the low\uffe2\uff80\uff90N fertilization treatment was enhanced after exposure to elevated CO2. This increase in soil respiration was not reflected in an increase in the microbial biomass of the L. perenne soil. The contribution of old and newly sequestered C to soil respiration, as revealed by the 13C\uffe2\uff80\uff90CO2 signature, reflected the turnover times of SOM\uffe2\uff80\uff93C pools as described by multipool SOM models. The results do not confirm the assumption of a negative feedback induced in the C cycle following an increase in CO2, as used in coupled climate\uffe2\uff80\uff93SOM models. Moreover, this study showed no evidence for a positive feedback in the C cycle following additional N fertilization.</p>", "keywords": ["2. Zero hunger", "organic-matter dynamics", "atmospheric co2", "leaf-litter", "global climate-change", "fumigation-extraction", "microbial biomass-c", "litter decomposition", "04 agricultural and veterinary sciences", "15. Life on land", "6. Clean water", "dioxide", "13. Climate action", "drying-rewetting frequency", "great-plains", "0401 agriculture", " forestry", " and fisheries"]}, "links": [{"href": "https://doi.org/10.1111/j.1365-2486.2004.00862.x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Global%20Change%20Biology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/j.1365-2486.2004.00862.x", "name": "item", "description": "10.1111/j.1365-2486.2004.00862.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1365-2486.2004.00862.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2004-10-25T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=microbial+biomass-c&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=microbial+biomass-c&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=microbial+biomass-c&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=microbial+biomass-c&offset=2", "hreflang": "en-US"}], "numberMatched": 2, "numberReturned": 2, "distributedFeatures": [], "timeStamp": "2026-09-20T23:02:47.650243Z"}